Tailoring of highly stable, size-controlled PtxNd/C catalysts via PVP-assisted Pt/C precursors

Platinum-rare-earth alloys are among the most active catalysts for the oxygen reduction reaction (ORR), yet a scalable synthesis route with control over nanoparticle size remains a considerable challenge. Here, we report a hybrid synthesis strategy utilizing size-controlled Pt/C nanoparticles, prepared via a modified polyol method with polyvinylpyrrolidone (PVP), as precursors for the subsequent alloying. Successful alloy formation is demonstrated with complete conversion to Pt 5 Nd observed for precursors of up to ∼8 nm while the large particle regime is retained, which is favorable for the elevated catalytic activity and long-term stability. The obtained Pt 5 Nd/C exhibits high ORR performance in rotating disk electrode (RDE) testing, with initial specific activity up to 4.6 mA cm −2 , and initial mass activity of up to 1.76 A (mg Pt) −1 . Most notably, the catalysts show remarkable durability under accelerated stress testing, with selected samples maintaining performance after up to 100,000 cycles. This work demonstrates that precursor-engineered Pt nanoparticles provide a viable and scalable pathway to highly durable Pt–rare-earth electrocatalysts and offers new insight into the structural evolution and stabilization of rare-earth–alloyed Pt nanoparticles.